Construction firm aims at space elevator in 2050

[kristopher]

I would have titled this "Construction firm muses about space elevator by 2050" if I had written the headline...

Construction firm aims at space elevator in 2050
The Yomiuri Shimbun

It may be possible to travel to space in an elevator as early as 2050, a major construction company has announced.

Obayashi Corp., headquartered in Tokyo, on Monday unveiled a project to build a gigantic elevator that would transport passengers to a station 36,000 kilometers above the Earth.

For the envisaged project, the company would utilize carbon nanotubes, which are 20 times stronger than steel, to produce cables for the space elevator.

The idea of space elevators has been described in several science-fiction novels. Obayashi, however, believes it is possible to construct one in the real world thanks to carbon nanotubes, which were invented in the 1990s, the company said.

Some other organizations...

http://www.yomiuri.co.jp/dy/national/T120221004421.htm

[GliderGuider]

1. I heard Dr Brad Edwards speak about the state of the research in 2005 or 2006

I heard him at a conference in Toronto. I was all like, "Srsly???"

I mean it's a cool idea in a "Tom Swift" kind of way, and "Fountains of Paradise" was such a nifty book. But in real life? Millions of tonnes of buckytubes? Srsly?

To what end, other than to satisfy our egoic desire to spray the galaxy with our seed?

[kristopher]

2. Construction cost vs current spending on satellite launches and space station missions

That would give a rough initial cost benefit. Then add in expanded opportunities such as the ability to deploy space based solar power.

I don't have a problem with the desire to spray the galaxy with our seed. Neither would Buddha.

[GliderGuider]

3. So what is a good cost estimate?

The numbers I googled up looked like they came out of a bong. Carbon nanotubes are currently going for $20 a gram or more. If we project a 90% drop in price, then a 100,000 km cable with an average diameter of 40 cm would cost on the order of $20 trillion dollars. Is that cable going to be thick enough? I have no idea.

It sounds like it's an order of magnitude less probable than backyard fusion generators.

[kristopher]

4. "If we project a 90% drop in price"

Why 90%?

For all you know nanotubes might be $20 a ton by 2040.

The point I was making is that there is a very large pool of money attracting interest in this technology.

What I was struck by was the 7 1/2 day ride up.

[GliderGuider]

6. Similar to taking a ocean liner across the Atlantic

I'm feeling less grumpy this morning, so I'll say it's an intensely romantic idea, both scientifically and for the human spirit. I remember running into the idea first in the mid-60s I was about 15 - well before Clarke's novel - and being blown away by it. I also thought we'd have a full-time Lunar presence and a few Mars missions under our belt by now.

As I now recall, in "Fountains of Paradise" (which was set in the 22nd century) it was Buddhists who opposed building the monstrosity, though I can no longer recall why. Maybe they objected to our egoic desire to spray our seed across the galaxy? Or maybe they were just Luddites who just didn't want to move out of the way.

[Dead_Parrot]

10. IIRC, the base of the tower was on a sacred mountain. nt

[muriel_volestrangler]

9. I don't think 'average diameter of 40cm' is a useful number

Here's a paper that reckons, even taking a lower value for the strength of nanotubes, the cable would weight 955 tons, to be able to lift a ton. So at $20/gram, that's about $20 * 1000 * 1000 * 955 = $19 billion per ton.

[GliderGuider]

12. The tensile strength is quite a bit better than I expected.

So to lift 25 tonnes the ribbon cost would be half a trillion dollars.

My real question is, if we actually had the 25,000 tonnes of CNT would it make economic sense to use them in this way, rather than use them milligram by milligram for other more earthbound purposes?

I suppose you could make a case that we wouldn't use them for space travel until they were a mere drop in the bucket of CNT production, as happened with chemical-fueled space travel.

I can't see anything that's so urgent out there that we can't do with lower-tech solutions. Kind of like the comparison between manned Mars missions and Mars Rovers, or manned missions to Saturn vs. Voyager.

[OKIsItJustMe]

11. Producing lower cost single-walled carbon nanotubes without metal catalysts

http://ipp.gsfc.nasa.gov/ft_tech_nanotech.shtm

[font face=Times, Times New Roman, Serif][font size=5]Producing lower cost single-walled carbon nanotubes without metal catalysts[/font]

[font size=4]NASA Goddard Space Flight Center has made a major step forward in reducing the cost of manufacturing single-walled carbon nanotubes (SWCNTs). Most manufacturing methods, which use a metal catalyst to form the tubes, have several drawbacks that have impeded development of SWCNTs’ numerous applications. NASA researchers have discovered a simple, safe, and inexpensive method to create SWCNTs without the use of a metal catalyst.[/font]

+ See Nanotailor success story
+ See ISM success story
+ See "Nanotechnology at NASA" video

[font size=4]Benefits[/font][font size=3]

• Less expensive: NASA’s SWCNT manufacturing process eliminates the costs associated with the use of metal catalysts, including the cost of product purification. As a result, the manufacturing cost can be reduced significantly for high-quality, very pure SWCNTs.


• More robust product: Because NASA’s process does not use a metal catalyst, no metal particles need to be removed from the final product. Eliminating the presence of metallic impurities results in the SWCNTs exhibiting higher degradation temperatures (650 °C rather than 500 °C) and eliminates damage to the SWCNTs by the purification process.


• Simpler and safer: Unlike most current methods—which require expensive equipment (e.g., vacuum chamber), dangerous gases, and extensive technical knowledge to operate—NASA’s simple SWCNT manufacturing process needs only an arc welder, a helium purge, an ice-water bath, and basic processing experience to begin production.


• Higher yield: Traditional catalytic arc discharge methods produce an “as prepared” sample with a 30% to 50% SWCNT yield. NASA’s method produces SWCNTs at an average yield of 70%.

…[/font][/font]

Research like this will continue to bring down the cost of carbon nanotubes. The limit to how low the cost might go is difficult to estimate, since the raw material is carbon.

Naturally, you would expect better prices if you were buying them by the ton, than you would if you were buying them by the gram.

Without a dramatic technology breakthrough:http://www.sti.nasa.gov/tto/Spinoff2009/ip_6.html

[font face=Times, Times New Roman, Serif][font size=5]Methods Reduce Cost, Enhance Quality of Nanotubes[/font]

[font size=4]Originating Technology/NASA Contribution[/font]

[font size=3]…

Using the NASA SBIR funding, SWeNT demonstrated that increasing the size of the fluidized bed reactor platform increased production capacity while decreasing cost. The SBIR support also provided another welcome outcome: higher quality nanotubes.

“When we invested in larger scale equipment, we also invested in more automation, instrumentation, and process controls,” says SWeNT CEO David Arthur. “That resulted in significant improvement in quality at the same time that we were expanding capacity and reducing cost.”

[font size=4]Product Outcome[/font]

In 2008, SWeNT opened a commercial-scale nanotube manufacturing plant. Since beginning operations at the 18,000-square-foot facility, Arthur says, the company has experienced a hundredfold increase in production coupled with a tenfold reduction in cost. SWeNT now offers two single-walled carbon nanotube product lines, as well as customized orders for the company’s hundreds of customers.

…

“Our vision is to once again increase our production scale a hundredfold and enjoy another tenfold reduction in cost,” says Arthur. At that point, he says, the company can even further reduce costs by recycling the CO feed gas used in the synthesis process—its most expensive production material.

…[/font][/font]

[tclambert]

5. 2050 is pretty far out to predict.

The killer robots could take over by then.

[malthaussen]

7. I don't like the idea of a space elevator

It is one big, fat, vulnerable target. And if somebody should bring it down... the results would be catastrophic.
And there is no such thing as complete security.

-- Mal

[phantom power]

8. It would be made out of a ribbon. Nothing much would happen if it "fell".

And the bulk of it would be flung off into space, as the center of mass would be slightly outside of the geosync orbital altitude.

[malthaussen]

13. Oh, I dunno about "nothing much."

Stipulating, per arguendo, that there would be no environmental impact if the earthside "anchor" were cut and the elevator brought down, you're still talking about significant loss of treasure, and whatever lives happen to be on the cable at the time. It is a lovely engineering idea, but I think the human element casts pretty heavy weight on the cost-benefit analysis.

-- Mal

[Nihil]

14. Not convinced of that PP ...

A two foot length of "ribbon" isn't going to do anything much.

A 36,000 km length of the same stuff *is* going to do quite a bit more.

And that's not allowing for the elevator itself and any other debris (nuts,
bolts, brackets, couplings, etc.) that will acquire a nice bit of kinetic energy
on the way down ...

Not that I'm concerned about it as I believe it is still firmly in the arena
of science fiction for the next couple of decades (at least) but if/when it
emerges as a real possibility, such things would have to be considered.

[kristopher]

15. Brings to mind the very real threat a nuclear plants targeted by terrorist poses.

[Nihil]

16. True - you'd build up a hell of a lot of KE if you dropped a nuclear plant from 36,000 km up ...

... not to mention all of the 36,000 km of really thick power cables that carry the
power being generated by the magically levitating nuclear plant.

Yep, I can see how that a succesful terrorist attack on that particular plant would
be a seriously bad event ... the effects of the radioactive fallout would be truly
trivial compared to the catastrophic damage caused by such immense energies.

(ETA: In fact it would be worse than having a major earthquake followed by a
tsunami over the same territory - thousands and thousands of deaths caused
by the event and millions of lives harmed by the after-effects.)

No disagreement there.

[phantom power]

17. Indeed, some shit will fall out of the sky.

I suppose what I'm saying is, it wouldn't be any worse in magnitude than, say, accidentally deorbiting a satellite, or skylab, etc. And any debris impact would be centered along the equator, which is mostly ocean.

The original concepts from SF for space elevators were more like actual structures -- like "a very large skyscraper 36,000 miles tall." Now, a thing like *that* falling down would be apocalyptic. A space elevator made of carbon nanotube ribbon, not especially apocalyptic.

[GliderGuider]

18. The issue is where the break occurs.

Theoretically everything above the break (including any manned control stations or transfer vehicles) gets sucked away from the Earth and flung off into space by the energy of the counterweight. Only the part below the break falls to Earth, but of course that could include cargo and personnel capsules...

And of course if the break occurs between geosync and the counterweight all bets are off.

I would not want to be a human being anywhere on or near the system when it malfed.

The whole thing is a stupid, unnecessary idea. Of course that has never stopped us before.